This invention relates to pest control arrangements especially for use in horticultural and gardening environments. The invention is more particularly concerned with a barrier to keep terrestrial gastropods, e.g., slugs and snails, out of a protected region to prevent damage to the plants from the gastropods.
There is a long-standing need for simple and effective means for blocking the entrance of slugs and snails into flower and vegetable gardens. Garden pests, and in particular gastropods such as snails and slugs, cause serious damage to gardens, killing young plants and damaging mature fruits, flowers, and vegetables. Garden slugs cause noticeable damage to leafy vegetables, such as cabbage and lettuce, and to many varieties of ornamental plants such as hosta. Slugs and snails are a problem to gardeners wherever there is moist soil, and thus are a quite prominent problem in the Great Lakes states, the Northeastern states, the Pacific Northwest, and the adjacent Canadian provinces.
Many attempts have been made to control gastropod invasions, but without much success. Typically, slug control arrangements contain an attractant, and attempt to lure the slugs into an area where they can be trapped or poisoned.
In Pence U.S. Pat. No. 5,390,441, an extruded garden stake has a channel and a slot opening, and there is a pest control chemical within the channel and accessible to a gastropod pest through the slot. A snail-attracting molluskicide bait is employed.
Cutter U.S. Pat. No. 4,756,116 shows a snail barrier that uses dissimilar metals to create a galvanic effect making it painful for the gastropod to cross.
Firth U.S. Pat. No. 4,566,219 shows a type of extruded plastic garden barrier fencing that carries a strip of a pesticide.
Other attempts have relied on various mechanical barriers. Some of these had employed barrier fencing for gardens, with a fiber member, i.e., rope, that is soaked in coal oil or tar, examples of which are discussed in Wiebrock U.S. Pat. No. 395,678 and Krause U.S. Pat. No. 392,347.
Accordingly, it is an object of this invention to provide a barrier for slugs and snails that does not draw the gastropods into the garden, but rather employs an irritant that stops the snails and slugs from crossing over into a protected area.
It is another object to: provide a slug and snail barrier that is low maintenance, and does not employ chemicals that are toxic or damaging to the plants in the garden.
All gastropods, i.e., snails and slugs, are sensitive to salt, i.e., sodium chloride. The salt burns their soft bodies. The system of this invention takes advantage of this fact, and dispenses salt though an absorbent, porous wicking material. Each time it rains and whenever the garden is watered, the wicking material becomes wet and draws more of the salt to the upper part of the barrier. This creates an irritant that the slug has to cross to enter the garden, and the slugs and snails will not cross the moist, salty barrier. The barrier arrangement thus comprises an elongated barrier, e.g., an plastic garden edging extrusion or other elongated flexible metal or plastic edge barrier that is adapted to extend along a margin of the garden. This can have a lower edge that protrudes a few inches into the soil and an upper edge that extends above the soil. A channel member is formed at an upper edge which holds a length of the wicking material. A paste of salt and other possible minor constituents is charged into the wicking material, with sufficient moisture and optionally a surfactant and/or a gelling agent to produce a desired consistency. As mentioned before, the salt is an irritant to terrestrial gastropods. Cayenne pepper and garlic juice can be added to the water and salt, as these are know to be deterrents to a number of insects and animals such as rabbits. A variety of other soluble, organic pest deterrents can be added to the system to inhibit destructive activities of other garden pests.
A synthetic compressed sponge material is used here as the wicking material, although other absorbent porous materials could be employed. Preferably the salt is applied in paste form into the sponge which is folded over and stuffed into the slot on the barrier. This provides a reservoir of salt so that each time it rains more of the salt is wicked up to the top edge.